Baby had fever. Eye became squint on 3rd day. Told due to weakness in 3rd nerve. Curing time?

I am divya.I have a 1 year 4 month old child . He had a fever for 3 days . after that he got cured from fever. But At the end of the 3rd day his right eye became squint . We did MRI scan . There was no problem associated with brain.He is very active and happy. he can run also. The doctor told that his 3rd nerve is weak . Also he told us to take omancortil syrup 10ml for 2 weeks. Now the 2nd weeks of the syrup consumption started . We are seeing a slight change for the squint eye . It is getting normal. But not completely cured. Hoe long it will take to get cured completely.....